Method of recording digital video and audio data

Abstract

A data word of 8 bits is code-transformed into a code word of 12 bits, for an 8/12 code which is suitable for high density recording such as d=2 and k=10, two kinds of synchronous pattern which never appear in data can be respectively provided for the video and audio uses while keeping the limitation with respect to d and k. Accordingly, decision error between the video data and audio data resulting from reproducing error can be significantly decreased, leading to an improvement in error probability and yet it is realizable with an extremely practical circuit structure. In addition, a pilot signal can be generated digitally with an extremely simple circuit, being suitable for home-use digital VCRs or the like which requires a stable pilot signal. As a result, the error rate of a super high density recording apparatus such as, for example, a digital VCR can be significantly decreased, and thus, its practical effects are very large.

What is claimed is: 
     
       1. A method of recording digital video data and digital audio data on a recording medium, each of the digital video and audio data being composed of a plurality of data words each consisting of a first specific number of bits, said method comprising the steps of: converting the plurality of data words in each of the digital video and audio data to a plurality of code words each consisting of a second specific number of bits larger than the first specific number of bits, respectively, and concatenating the plurality of code words converted from each of the digital video and audio data so as to obtain a continuous bit sequence satisfying a condition wherein a number of bits having a same binary value and occurring continuously is within a range of from 2 to 10;   adding a first synchronous pattern having a first specific bit pattern, which consists of a third specific number of bits and which fails to occur in said continuous bit sequence, to a beginning end of said continuous bit sequence obtained from the digital video data and a second synchronous pattern having a second specific bit pattern, which consists of the third specific number of bits and which fails to occur in said continuous bit sequence, to a beginning end of said continuous bit sequence obtained from the digital audio data, said first specific bit pattern of said first synchronous pattern being different from said second specific bit pattern of said second synchronous pattern; and   recording each of said continuous bit sequences added to said first synchronous pattern and said continuous bit sequences added to said second synchronous pattern on the recording medium;   wherein said first specific number of bits of each of said data words is 8, and said second specific number of bits of each of said code words is 12.   
     
     
       2. The method according to claim 1, wherein said second specific bit pattern of said second synchronous pattern is such a pattern that all bits of said first specific bit pattern of said first synchronous pattern are inverted. 
     
     
       3. A method of recording digital video data and digital audio data on a recording medium, each of the digital video and audio data being composed of a plurality of data words each consisting of a first specific number of bits, said method comprising the steps of: converting the plurality of data words in each of the digital video and audio data to a plurality of code words each consisting of a second specific number of bits larger than the first specific number of bits, respectively, and concatenating the plurality of code words converted from each of the digital video and audio data so as to obtain a continuous bit sequence satisfying a condition wherein a number of bits having a same binary value and occurring continuously is within a range of from 2 to 10;   adding a first synchronous pattern having a first specific bit pattern, which consists of a third specific number of bits and which fails to occur in said continuous bit sequence, to a beginning end of said continuous bit sequence obtained from the digital video data and a second synchronous pattern having a second specific bit pattern, which consists of the third specific number of bits and which fails to occur in said continuous bit sequence, to a beginning end of said continuous bit sequence obtained from the digital audio data, first specific bit pattern of said first synchronous pattern being different from said second specific bit pattern of said second synchronous pattern; and   recording each of said continuous bit sequences added to said first synchronous pattern and said continuous bit sequences added to said second synchronous pattern on the recording medium;   wherein one of said first specific bit pattern of said first synchronous pattern and said second specific bit pattern of said second synchronous pattern is `111110011111111110011111` and the other of said first and second specific bit patterns is `000001100000000001100000`.   
     
     
       4. A method of recording digital video data and digital audio data on a recording medium, each of the digital video and audio data being composed of a plurality of data words each consisting of a first specific number of bits, said method comprising the steps of: converting the plurality of data words in each of the digital video and audio data to a plurality of code words each consisting of a second specific number of bits larger than the first specific number of bits, respectively, and concatenating the plurality of code words converted from each of the digital video and audio data so as to obtain a continuous bit sequence satisfying a condition wherein a number of bits having a safe binary value and occurring continuously is within a range of from 2 to 10;   inserting one or more continuous bits of binary value `1` and one or more continuous bits of binary value `0` into said continuous bit sequence alternately at predetermined intervals while keeping the condition that the number of bits having a same binary value and occurring continuously is within the range of from 2 to 10:   adding a first synchronous pattern having a first specific bit pattern, which consists of a third specific number of bits and which fails to occur in said continuous bit sequence, to a beginning end of said continuous bit sequence obtained from the digital video data and a second synchronous pattern having a second specific bit pattern, which consists of the third specific number of bits and which fails to occur in said continuous bit sequence, to a beginning end of said continuous bit sequence obtained from the digital audio data, said first specific bit pattern of said first synchronous pattern being different from said second specific bit pattern of said second synchronous pattern; and   recording each of said continuous bit sequences added to said first synchronous pattern and said continuous bit sequences added to said second synchronous pattern on the recording medium;   wherein said first specific number of bits of each of said data words is 8, and said second specific number of bits of each of said code words is 12.   
     
     
       5. The method according to claim 4, wherein said second specific bit pattern of said second synchronous pattern is such a pattern that all bits of said first specific bit pattern of said first synchronous pattern are inverted. 
     
     
       6. A method of recording digital video data and digital audio data on a recording medium, each of the digital video and audio data being composed of a plurality of data words each consisting of a first specific number of bits, said method comprising the steps of: converting the plurality of data words in each of the digital video and audio data to a plurality of code words each consisting of a second specific number of bits larger than the first specific number of bits, respectively, and concatenating the plurality of code words converted from each of the digital video and audio data so as to obtain a continuous bit sequence satisfying a condition wherein a number of bits having a same binary value and occurring continuously is within a range of from 2 to 10;   inserting one or more continuous bits of binary value `1` and one or more continuous bits of binary value `0` into said continuous bit sequence alternately at predetermined intervals while keeping the condition that the number of bits having a same binary value and occurring continuously is within the range of from 2 to 10;   adding a first synchronous pattern having a first specific bit pattern, which consists of a third specific number of bits and which fails to occur in said continuous bit sequence, to a beginning end of said continuous bit sequence obtained from the digital video data and a second synchronous pattern having a second specific bit pattern, which consists of the third specific number of bits and which fails to occur in said continuous bit sequence, to a beginning end of said continuous bit sequence obtained from the digital audio data, said first specific bit pattern of said first synchronous pattern being different from said second specific bit pattern of said second synchronous pattern; and   recording each of said continuous bit sequences added to said first synchronous pattern and said continuous bit sequences added said second synchronous pattern on the recording medium;   wherein one of said first specific bit pattern of said first synchronous pattern and said second specific pattern of said second synchronous pattern is `111110011111111110011111` and the other of said first and second specific bit patterns is `000001100000000001100000`.